Treating comminuted solids with liquids.



No.894,417. 'PATENTEDJULY28,1908.'

Y A. ADAIR. TREATING GOMMINUTED soups WITH LIQUIDS.

APPLICATION FILED JULY 5. 1907. 2 SHEETS SHBET No. 894,417. PATENTED JULY 28, 1908.

A. ADAIRL TREATING GOMMINUTED SOLIDS WITH LIQUIDS.

APPLICATION FILED JULY 1 5 907 2 SHEETS-SHEET 2.

ALFRED ADAIR, OF JO1L\\'NESBURG, TRANSVAAL.

TREATING COMMINUTED SOLIDS WITH LIQUIDS.

Specification of Letters Patent.

Patented July 28, 1 908.

Applicatiori filed July 5, 1907. Serial No. 382,346.

To all VF/HM! it may concern:

Be it known that 1, ALFRED Anon, a subject. of the King o'l Great Britain, residing at 16A ()verbeek street, .lro veville, Johannesburg, in the (olony of the lransvaal, have .invented certain new and useful linprovements in .lrealing (omminuted Solids with liiquids, ol' which the following is a specification.

The present invention relates to the treatment with liquids o'l comn-iinuted solid matter; as for example the treatment of line auriferous sands and slimes by cyanid, for the purpose o'l' dissolving the metallic constituents oi the former; the treatnnmt of other comminutml metalliierous ores and products, by solvents, or the treatment of mods containing valuable salts, or the washing of ores, muds or chemical precipitates.

The purpose in view is to-provide a process capable of continuous operation wherein the trmitmenl. is more ollieientand rapid than heretofore and wherein the volume of liquid requisite for thorough treatment is minimized,sothat int-he case of solvents or Washes they are relatively more enriched in respect of their valuable contents.

According to the present process the coinminuted solid is delivered as a thick pulp into the upper regions of a body of liquid and is caused to gravitate downwardly through the same and re-collect as a thick pulp at the bottom of the liquid; While an upward current usually of low velocity is set up through the liquid. lhe rate of flow and the manner of distributing the pulp and liquid respectively are such that clear liquid collects at the surface of the body of liquid and may be continuously witlulrawn therefrom. The treatment is usually carried out in a series of stages; the thickened pulp collected at the termination of the first stage being re-delivercd to a seemid body of .litplidthrough which it gravitates in the second stage of the process and so on. lhirthermore, the stages are coordinated in such manner that as the liquid passes through the several steps of the process from the last to the first it meets successively richer or less conqiletely treated portions oi" the solid matter; in other words the fresh liquid operates upon. the ,most imioverished or fully treated solid, While the liquid about to be withdrawn is iinally enriched by contact with the freshest and therefore most amenable solids. A further feature of the invention is the agitation of the pulp between each stage with liquid and its conveyance to the next stage thereby.

In the accompanying drawings is shown suitable apparatus for treating auriferous tine sands or slimes with cyanid in accordance with the spirit of this invention: Figure I being a conventional elevation of the plant, the interior of one of the treatment vats being shown; and Fig. H a section at right angles to the plane oi Fig. I through the first of the treatment vats. Figs. lll'and 1V illustrate an ordinary vat adapted. for the. purposes of the invention, the loriner being a sectional side view and the latter a plan.

Referring to Figs. I and II, there is incl uded in the apparatus, a series of identical treatment vats a a a, arranged one sme- What higher than the other from the first 01. to the last a.

Each vat is preferably con structed with a pointed bottom I) in order to facilitate the settlement and concentration of the slimes therein. The several vats are also provided with upper distrilmters c, c, c for slimes and lower distributors d, d for solution, said distrilmters being adapted to distribute their teed uniformly over the whole area of each vat. Each vat is further provided with a decanting pipe, 0 e e for drawing ofi' clear liquid at the surface.

f, f f indicate series of pulp collectors arranged in the pointed bottoms, each such series leading to a common eduction pipe, which latter are indicated by g g and g Pulp is supplied to the upper distributors by pumps 71., k and 7r, each of said pumps except the first 71- drawing its supplies from the eduction pipe of the preceding vat. The eduction pipe of the last vat a discharges to waste, the movemcnt of the pulp being assisted by a jet of water supplied through pipe 71. Pump h draws its supply from the settling tank hereafter mentioned.

Liquid passes froin'the decanters by the pipes j, f, j. Of these and are c0nnected respectively to the valves Te -and k controlling the feed to the, lower distributors ofthe vats o and a Pipe 7' asses liquid to the precipitation boxes Z; Whi e. liquid is supplied. to the last vat a through valve 76 and the pipe m. i

In order to assist movement of the slimes in the cduction pi es 5 g, and g to the slimes pumps, liquir is supplied to such eduction pipes by small valve controlled pipes n 97, and if. The liquid is'in each case drawn from the feed to the vat to which the pulp with which the liquid is mixed is about to be assed; for instance pipe n conducts liquid i'rol'n pipe m to eduction pipe g from which pulp passes to vat a and similarly pipe n leads to eduction pipe g.

0 is a settling tank having notches p for conducting superfluous water to waste. Such settling tank is constructed with a pointed bottom, and,'like the'treatment vats, is rovided with a slimes collector, and an er uction pipe Q. As already mentioned the pump 71, dra -rs from said eduction pipe q, to which moreover pipe n is arranged to pass liquid.

'1" is a sum to which impoverished solution is conducte from thepre'cipitation boxes Z.

by launder s, and t indicates a pump for passing solution from sump r to vat a by way of the pipe m and valve it already referred to.

' The several pumps h, k h and t are shown as being driven off a single shaft 11L.

Although for the sake of convenience only three treatment vats are illustrated and described, it is to be understood that in practice their number may be varied as may appear desirable.

The plant described is operated in the following manner. The vats being preliminarily filled with solution, the slimes from the reduction plant, hydraulic classifiers or otherwise, are run continuously into the settling tank 0, where the solid constituent settles and concentrates at the bottom, while the separated water runs oil by way of the notches p. The settled slimes are now withdrawn by the pump k delivered to the upper distributer of vat a and thereby caused to difi'useand gravitate through the mass of liquid therein. Settling at the bottom as a thick pulp comparatively free from solvent, the slimes are withdrawn from vat a by the pump 71, and delivered to the upper distributer of the vat c and so on through the series, until they are dischar ed to waste through the pipe 9 Meanwhi e fresh liquid is continuously supplied by the pump t to the lower distributer d of the vat a and rising up through the gravitating slimes collects in a clear state at the surface of the vat contents. A relatively smaller volume of fresh solvent is also passed by pump '1? through the pipe n to the thick slimes which are about to be pumped to vat (L The purpose of this is to thin such slimes suflicientfl'y to enable them to be readily pumped, while avoiding the withdrawal with them of an undue uantity of gold-containing solution. A furt er purpose is to effect a thorough a itation of the slimes with solvent, between t e stages, with the object of facilitating the extraction of the gold therefrom. The clear liquid collected in vat a is withdrawn through the decanter e and pipe 7' and the bulk of it is fed to the distributer d of the preceding vat a wherein it rises and re-collects at the surface as clear liquid. The portion which is not fed to distributer d is led on by pipe at to the eduction pipe 9 Passing thus through the whole of the treatment vats the liquid is at last withdrawn by pipe j and conducted to the extractor boxes Z for the removal of its gold contents, being subsequently returned to the sump r to make the circuit again. I

'0 is a feed pipe through which fresh cyanid may be introduced as re uired to replace that finally carried away with the discharged slimes or otherwise lost, the advantage of introducing it at such point being that a certain pro ortion of it is carried over with the enricher solution to the precipitation boxes and assists the operation of precipitation.

Where it is desirable to retard the motion of the'solids in the liquid, as for example where sands are being treated, baffles .10 such as are shown on the left of Fig. 11 may be fitted in the-vats, such bafiles being preferably pointed at the top, to prevent accumulation of the solid matter upon them.

In applying the invention to existing cyanid treatment vats, of the usual circular type, as the vat floors are usually flat or insuflicientlysloped to permit the ready discharge of the slimes collected at the bottom, means are provided as shown in Figs III and IV to loosen the settled pulp from the bottom and pass it from the periphery to the center, where the outlet valve :1: is situated. Such means, as illustrated, consist in a central vertical shaft y revoluble by the spur wheels 2 and the driven shaft 1. Said shaft 1/ carries propeller blades 2 shaped to fit closely to the bottom of the vat and sodirected as to pass the pulp inwards and downwards. The other fittings of the vat are similar to those already described; 3 being the decantation pipe, 4 the upperv and 5 the lower distributer and 6 the pipe for supplying fluid to the thickpulp.

It is important in carrying out the process in the most efficient manner to concentrate the slimes as much as possible at the termination of each stage in order that as little as possible of the treatment liquid may be carried back against the main flow between each sta e. dis harged with the impoverished slimes consists of substantially pure cyanid carrying an inappreciable amount of gold and therefore as a rule no final washin is required. Where desirable however a fina -wash'of water or other liquid may be given in apparatus similar to the treatment vats already described, for the purpose of recovering the treatment liquid. discharged with the residues.

It is evident that instead of arranging thev vats in an ascending series as described, they. may be arranged to descend, the solution being pumped and the pulp moving by gravity;

It will be seen that the liquid finally or again the vats may be leveled and both sof lution and pulp may be pumped. It is how- .130

ever preferred to pum the pulp in order that it may be more comp etely agitated with solution between each stage.

It is to be understood that certain advan tages of the invention may be attained by carrying out the treatment in one stage onl more particularly when the solids are readi y amenable to the liquid. Thus, in such cases the process maybe made'continuous, the pulp after gravitating through the liquid being collected and drawn off in aconcentrated condition separated to a large extent from the washing liquid, while the enriched solution may be continuously drawn oft from above, free of pulp. It is evident however that the most perfect separation of valuable liquid from the pulp can be best effected by conductin the process in sta es, as described, wliich method also enables the very desirable graduation oi the freshness of the liquid in accordance with the impoverishment of the solid matter.

I claim as my invcntion:-

solids with iquids, which consists in effecting the treatment in stages, each stage co1nprising the steps of distributing the solid matter as a concentrated pulp to the up er part of the body of liquid causing it to (ifiuse and gravitate through the same, re-collecting it as concentrated pulp below the liquid, distributing liquid in the lower part of the body of liquid so as to produce an upward current therein and collecting clear liquid at the .surface; which consists further in supplying pulp collected at each stage as feed in the succeeding stage, supplying one portion of 1. The process of treating comminuted the clear liquid collected at each stage as feed in the preceding stage and agitating the other portion of such liquid with the ul about to be fed in such preceding stage, resii ulp'beilig supplied in the first stage, fresh iquid being supplied as feed in the last stage and fresh hqui being also agitated with the pulp about to be fed in the last stage.

2. A continuous rocess of treating coniminuted solids with iquids, which consists in effecting the treatment in stages, each stage comprising the step a (idistributing the solid matter as a concentrated pulp to the upper art of the body of liquid causing it to diffuse and gravitate through the same, re-collecting it as concentrated pulp below the liquid, distributing liquid in the lower part of the body of liquid so as to produce an upward current therein and collecting clear liquid at the surface; which consists further in sup plying pulp collected at each stage as feed in the succeeding stage, supplying one portion of the clear liquid collected at each stage as feed in the preceding stage and agitating the other portion of such liquid with the )ul about to be fed in such preceding stage, i resii pulp being continuously supplied in the first stage, fresh liquid being continimusly supplied as feed in the last stage and fresh liquid eing also agitated with the pulp about to be fed in the last stage.

, In testimony whereof I ailix my signature in presence of two witnesses.

ALFRED ADAIR.

.Vitnesses: I

ALFRED L. Sroon, WESLEY E. JOHN. 

